Put in a youtube URL of just about any format and get back the ID

parse_youtube_url.php

<?php
function parse_youtube_url($url){
  $id = '';
  preg_match("/^.*(youtu.be\\/|v\\/|u\\/\\w\\/|embed\\/|watch\\?v=|\\&v=)([^#\\&\\?]*).*/uism", $url, $matches);
  if( isset($matches[2]) ){
    $id = $matches[2];
  }	
  return $id;
}